advice on engine rebuild

[Newton]

Ok need some advice guys...my engine picked up a knock after my drunk friend revved it very very hard like floored the gas pedal for a good couple seconds...after that i lost power like it was running on 5 cylinders and when i start the truck it would turn over fine and then after it starts would hear a very loud grinding noise for like 3 seconds then go away but would hear a light knocking sound coming from the engine was hoping it was my flex plate getting loose but with my luck after i dropped the transmission and checked it ..flex plate seems fine...so anyone have an idea what damage i'm faced with?... i have a 4.0 sitting in a parts xj only block and head intact no intake exhaust nothing just block and head...can i use anything from that engine like the block or head or something for my renix..or do i have to rebuild my engine and or upgrades...stroker?...v8?...ls?... what you guys think? what are my options?

[Eagle]

Everything you have mentioned is an option -- the question is, what are your priorities? Do you need to a fast & cheap swap to get it running, or do you want to put more time/effort/money into it to have an engine that will start out like new (the rebuild route)? Are you satisfied with the performance a stock 4.0L gives you, or do you want to boost the power as long as you're doing something?

[big66440]

I think your "friend" is not really a friend,,,, just saying.

[SBpunk]

These guys know more than me but I just did a rebuild. Decided to go with a stock rebuild since money was an issue. More importantly than that I built mine to last 20+ years. If I was going to beat her up more I would've done a 4.2 crankshaft / lifters etc. Cheap alternative and doesn't take a lot of aftermarket stuff. You can run stock injectors, don't have to fill up with high octane liquid gold and you still get enough power to feel it. Only reason I know is I took a buddies XJ out that was stroked with the 4.2 build. 

[Newton]

 .

[Newton]

Everything you have mentioned is an option -- the question is, what are your priorities? Do you need to a fast & cheap swap to get it running, or do you want to put more time/effort/money into it to have an engine that will start out like new (the rebuild route)? Are you satisfied with the performance a stock 4.0L gives you, or do you want to boost the power as long as you're doing something?

 

 

I think your "friend" is not really a friend,,,, just saying.

 

 

These guys know more than me but I just did a rebuild. Decided to go with a stock rebuild since money was an issue. More importantly than that I built mine to last 20+ years. If I was going to beat her up more I would've done a 4.2 crankshaft / lifters etc. Cheap alternative and doesn't take a lot of aftermarket stuff. You can run stock injectors, don't have to fill up with high octane liquid gold and you still get enough power to feel it. Only reason I know is I took a buddies XJ out that was stroked with the 4.2 build. 

 

Definately wanna get it running eagle asap but if i'm able to to do that on a cheap and gain a little more power i don't mind..also i think the 4.0 has enough power for me and don't mind if i have to leave it stock...just wanna get it back on the road and i agree with u big66440 i starting to question that friendship

[Minuit]

The quickest way to get it back on the road will be to swap in a new long block keeping your Renix equipment.

[Newton]

The quickest way to get it back on the road will be to swap in a new long block keeping your Renix equipment.

Long block meaning block and head right?..also can I use the one from my 2000 parts Xj and bolt on all Renix components?

[Eagle]

 

Definately wanna get it running eagle asap but if i'm able to to do that on a cheap and gain a little more power i don't mind..also i think the 4.0 has enough power for me and don't mind if i have to leave it stock...just wanna get it back on the road and i agree with u big66440 i starting to question that friendship

 

 

Then I would either rebuild the original engine to stock specs, or take the XJ engine, replace the main and rod bearings, and drop that in. The idea of a stroker engine is attractive, but it can't be done on the cheap. There are subtle differences between the 4.0L and 4.2L engines. You obviously can't use stock 4.0L pistons with a 4.2L crank, so you have to decide if you want to use the skinnier 4.2L  connecting rods or the stronger 4.0L connecting rods, then you have to source pistons that will work with whatever rods you choose to get the right deck height. There may be aftermarket pistons available today that will work, but when I looked into it a number of years ago the available combinations resulted in overly high compression ratio, which meant running premium-grade gas AND having to be very careful about "quench." For me it wasn't worth it.

[Minuit]

 

The quickest way to get it back on the road will be to swap in a new long block keeping your Renix equipment.

Long block meaning block and head right?..also can I use the one from my 2000 parts Xj and bolt on all Renix components?

 

http://cruiser54.com/?p=100

[Newton]

 

 

Definately wanna get it running eagle asap but if i'm able to to do that on a cheap and gain a little more power i don't mind..also i think the 4.0 has enough power for me and don't mind if i have to leave it stock...just wanna get it back on the road and i agree with u big66440 i starting to question that friendship

 

 

Then I would either rebuild the original engine to stock specs, or take the XJ engine, replace the main and rod bearings, and drop that in. The idea of a stroker engine is attractive, but it can't be done on the cheap. There are subtle differences between the 4.0L and 4.2L engines. You obviously can't use stock 4.0L pistons with a 4.2L crank, so you have to decide if you want to use the skinnier 4.2L  connecting rods or the stronger 4.0L connecting rods, then you have to source pistons that will work with whatever rods you choose to get the right deck height. There may be aftermarket pistons available today that will work, but when I looked into it a number of years ago the available combinations resulted in overly high compression ratio, which meant running premium-grade gas AND having to be very careful about "quench." For me it wasn't worth it.

 

 

 

 

 

The quickest way to get it back on the road will be to swap in a new long block keeping your Renix equipment.

Long block meaning block and head right?..also can I use the one from my 2000 parts Xj and bolt on all Renix components?

 

http://cruiser54.com/?p=100

 

 

Decided i will swap in the xj engine has less than 100k running on there so i will just skip changing the bearings and put that money towards rebuilding the original engine if anything were to happen later down the line i'l swap back in the original...i was taking a look at cruiser's post on the renix into ho swap and everything seems to be pretty straight forward except the distributor indexing thingy is there a video out there on it and elaborate a little more on why i have to do it last time i took out the distributor i just dropped it back in and seemed to work fine or so i thought??.. :dunno:

[MJ H.O.]

I installed a 232 crankshaft shaft out of a 1973 cj5 in a low mileage 1996 4.0 block with stock rods, stock pistons. You Must use a 0.051" compressed head gasket. The quench height is 0.030" and the static compression is 9.7 to 1 with dynamic at 8.5 to 1

Add a 1996 camshaft and 1.7 yellaterra roller rockers, pull the head use a carbide bit on the push rod holes for clearance. They fit under the 96-up steel valve cover. 1.7s are great as well as the 9.7 compression from the 232 crankshaft

Add a 99 up intake manifold. Match the ports to the head.

If you port the head focus on cleaning up the bowls and shaping the valve guides.